Fastest & Tallest Growing Ornamental Grasses

Bamboo

• A common choice for screening, bamboo is a fast-growing grass that is evergreen in the climates where it thrives. It reaches its full height in only a year or two. Running bamboo needs to be grown in large, deep containers made of concrete, steel or weather-proof ceramic. But clumping bamboos enlarge outward, without running roots, so can be planted in the ground. Some clumping varieties, such as Borinda boliana, grow to 24 feet. Clumping bamboo is hardy to 10 degrees Fahrenheit.

Giant Reed Grass

• The tallest ornamental grass commonly used in landscaping, giant reed grass (Arundo donax), comes in green or green-and-white striped varieties. It resembles a corn plant and reaches 20 feet tall with stems 1 inch in diameter. In the fall, it produces plumes of reddish-brown that age to parchment. It prefers full sun but will tolerate part sun; it grows most quickly with regular water and spreads slowly by rhizomes. Arundo donax is hardy to minus 15 degrees.

Plume Grass

• Plume grass, or ravenna grass (Erianthus ravennae), is sometimes called hardy pampas grass, because it resembles pampas grass (Cortaderia sellioana), forming a wide clump of gray-green foliage about 5 feet tall, topped by fluffy, buff-colored plumes on long, thin stems. The plumes reach 6 feet above the foliage. Pampas grass is hardy only to 15 degrees and is considered invasive in some states. Plume grass is hardy to minus 10 degrees. Plant it in full sun and well-drained soil. Like pampas grass, it self-seeds.

Giant Silver Grass

• Miscanthus giganteus, also sometimes listed as M. floridulus, reaches 12 to 15 feet by its second year. It grows in a vase shape, forms a large clump about 6 feet wide and is hardy to minus 25 degrees. Its leaves are green, with a silver midrib, and it blooms in fall with an airy wine-colored plume. While not truly evergreen, its stems remain upright in the garden through the winter. It enjoys full sun and regular water.